Mood Instability . . . PMDD or Bipolar Disorder . . . Or Both?

I am a 29 yo mother and was diagnosed as being bipolar at approximately 25 yo. I have taken a variety of medications(lamicatal, fluoxetine, topamax, lithium) and respond but i have always had “flare-ups” of exaggerated moodiness(rage, sadness, etc) about 2 weeks before my period. Since I have been married my husband has been able to predict my moods based on my the timeframe of my periods and I had NO symptoms of my mood disorder while pregnant. In fact, I felt better moodwise pregnant than I did at any other point of my life, period! So my question is, do u think I could have PMDD vs. bipolar? Is that a viable misdiagnosis?

Veeeeerrrryyyy interesting question.  At the root of this is the question of what exactly is a Bipolar Disorder and is ALL mood instability a flavor of Bipolar or can it be something else.  The problem with thinking of all mood instability as Bipolar Disorder is that it “waters down” and makes the diagnosis less meaningful.  The diagnostic criteria for Bipolar Disorder come from the “Diagnostic and Statistical Manual” or DSM (currently in the 4th edition–treatment revision or . . . DSM IV-TR).  The criteria are supposed to be diagnostic, but also statistically relevant.  By this I mean that meeting the criteria will statistically predict your response to a specific treatment and predict what the course of the illness will be.   If the criteria are too broad, it lessens the DSM’s effectiveness as a predictive tool.  Establishing a diagnosis for someone can be quite difficult, however.  When I do an evaluation, I get a slice of time in that person’s life.  The diagnostic criteria are longitudinal criteria . . . that there is a progression of symptoms over time.  A waxing and waning.  And the timing of the ebb and flow of symptoms plays a strong role in deciding what the ultimate diagnosis is.  There is big danger in not keeping this in mind.  For example, there is nothing to distinguish the depression of Major Depression from the depression of Bipolar Disorder, Most Recent Episode Depressed (yes, Virginia, that is the official name of the disorder).  It is only looking at the progression of symptoms over time that one can see the presence of manic or hypomanic symptoms that then changes the diagnosis to one of Bipolar Disorder.

With that in mind, what would we call someone who has symptoms of Bipolar Disorder only in the last two weeks of her cycle?  If it was, indeed, true symptoms of Bipolar Disorder (ie, meeting the specific criteria of Mania or Hypomania), then we would call it a Bipolar Disorder.  Regardless of the specific cause.  The intervention, however, might be quite different.  Certainly there is room for use of a mood stabilizer in this circumstance, but that would seem to be a band-aid to me.  People’s brains are very heavily influenced by hormonal factors . . . men and women . . . and probably more than we understand at present.  It would seem to me that the better intervention for someone with this specific pattern of mood instability would be to treat this hormonally. Some birth control pills are quite effective at reducing late cycle mood instability, especially that characterized by irritability and sadness.  In fact, as you describe, your symptoms are more consistent with a PMDD picture rather than Bipolar Disorder.  Unfortunately, you are allowed to have both.  If you meet criteria for Mania or Hypomania, you have a Bipolar Spectrum illness.  Anger/irritability, however, is not sufficient to meet criteria for Mania or Hypomania, so unless you have other features of these disorders, you may have been misdiagnosed.

–Dan Hartman, MD